Quite a few pre-Columbian beads are called "jade," when "green-stone" might be preferable. "Green-stone" encompases a variety of materilas, but these are often something like granite with something greenish in it. Some specimens tend greatly toward gray.

These beads can be judged on their artistic merit rather than material. After all, some beautiful prase beads and pendants were made in antiquity.

There are also many imitations of these beads, recently made in Guerrero, Mexico, that can be pretty convincing.

Not to be crass, but I would have to judge your bead to be sort of low in quality, in terms of its carving--though beauty is in the eye of the beholder. (I'm replying because no one else has had anything to say for several days--and I am not one to flatter or beat-around-the-bush.

It's a nice piece for what it is.

Jamey